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Aamer M, Siddiqui M, Jabeen A, Irshad R, Khan FA, Atia-tul-Wahab, Iqbal Choudhary M, Wang Y. New anti-inflammatory and non-cytotoxic metabolites of methylstenbolone obtained by microbial transformation. Bioorg Chem 2022; 129:106187. [DOI: 10.1016/j.bioorg.2022.106187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 07/03/2022] [Accepted: 09/29/2022] [Indexed: 11/02/2022]
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2
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Medaka embryos as a model for metabolism of anabolic steroids. Arch Toxicol 2022; 96:1963-1974. [PMID: 35352155 PMCID: PMC9151555 DOI: 10.1007/s00204-022-03284-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/14/2022] [Indexed: 01/07/2023]
Abstract
In anti-doping science, the knowledge of drug metabolism is a prerequisite to identify analytical targets for the detection of misused prohibited substances. As the most obvious way to study xenobiotic metabolism, the administration to human volunteers, faces ethical concerns, there is a need for model systems. In the present study, we investigated whether Oryzias latipes (medaka) embryos might be an alternative, non-animal test model to study human-like metabolism. In the present study, we exposed medaka embryos at the morula stage to the anabolic steroid metandienone (10 µM or 50 µM) for a period of 2 or 8 days. According to the fish embryo toxicity test (OECD test), we assessed the developmental status of the embryos. We further investigated metandienone metabolites by high-performance liquid chromatography- and gas chromatography-mass spectrometry. Medaka embryos produced three mono-hydroxylated and one reduced metabolite known from human biotransformation. Developmental malformations were observed for the exposition to 50 µM metandienone, while a significant elevation of the heart beat was also present in those individuals exposed to the lower dose for 8 days. The present study demonstrates that the medaka embryo represents a promising model to study human-like metabolism. Moreover, the judgement of developmental parameters of the fish embryos enables for the simultaneous assessment of toxicity.
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Aamer M, Siddiqui M, Jabeen A, Irshad R, Khan FA, Atia-Tul-Wahab, Choudhary MI, Wang Y. Structural transformation of methasterone with Cunninghamella blakesleeana and Macrophomina phaseolina. RSC Adv 2022; 12:9494-9500. [PMID: 35424863 PMCID: PMC8985176 DOI: 10.1039/d2ra01396g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
An anabolic-androgenic synthetic steroidal drug, methasterone (1) was transformed by two fungi, Cunninghamella blakesleeana and Macrophimina phaseclina. A total of six transformed products, 6β,7β,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (2), 6β,7α,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (3), 6α,17β-dihydroxy-2α,17α-dimethyl-5α-androstane-3,7-dione (4), 3β,6β,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-7-one (5), 7α,17β-dihydroxy-2α,17α-dimethyl-5α-androstane-3-one (6), and 6β,9α,17β-trihydroxy-2α,17α-dimethyl-5α-androstane-3-one (7) were synthesized. Among those, compounds 2–5, and 7 were identified as new transformed products. MS, NMR, and other spectroscopic techniques were performed for the characterization of all compounds. Substrate 1 (IC50 = 23.9 ± 0.2 μg mL−1) showed a remarkable anti-inflammatory activity against nitric oxide (NO) production, in comparison to standard LNMMA (IC50 = 24.2 ± 0.8 μg mL−1). Whereas, its metabolites 2, and 7 showed moderate inhibition with IC50 values of 38.1 ± 0.5 μg mL−1, and 40.2 ± 3.3 μg mL−1, respectively. Moreover, substrate 1 was found to be cytotoxic for the human normal cell line (BJ) with an IC50 of 8.01 ± 0.52 μg mL−1, while metabolites 2–7 were identified as non-cytotoxic. Compounds 1–7 showed no cytotoxicity against MCF-7 (breast cancer), NCI-H460 (lung cancer), and HeLa (cervical cancer) cell lines. Fungal transformation of methasterone resulted in six products (2–7). 2–5, and 7 were identified as new. Substrate 1 showed remarkable anti-inflammatory activity but was cytotoxic. Products 2 and 7 showed moderate activity but were non-cytotoxic.![]()
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Affiliation(s)
- Muhammad Aamer
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan
| | - Mahwish Siddiqui
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan
| | - Almas Jabeen
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
| | - Rimsha Irshad
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan
| | - Farooq-Ahmad Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan .,Third World Center (TWC) for Chemical Sciences, International Center for Chemical & Biological Sciences, University of Karachi 75270 Pakistan
| | - Atia-Tul-Wahab
- Dr Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan
| | - M Iqbal Choudhary
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan .,Dr Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi Karachi 75270 Pakistan.,Department of Biochemistry, Faculty of Science, King Abdulaziz University Jeddah-21589 Saudi Arabia
| | - Yan Wang
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi Karachi-75270 Pakistan
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Piper T, Fusshöller G, Schänzer W, Lagojda A, Kuehne D, Thevis M. Studies on the in vivo metabolism of methylstenbolone and detection of novel long term metabolites for doping control analysis. Drug Test Anal 2019; 11:1644-1655. [DOI: 10.1002/dta.2736] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/31/2019] [Accepted: 11/10/2019] [Indexed: 01/21/2023]
Affiliation(s)
- Thomas Piper
- Center for Preventive Doping ResearchGerman Sport University Cologne Cologne Germany
| | - Gregor Fusshöller
- Center for Preventive Doping ResearchGerman Sport University Cologne Cologne Germany
| | - Wilhelm Schänzer
- Center for Preventive Doping ResearchGerman Sport University Cologne Cologne Germany
| | | | - Dirk Kuehne
- Crop Science DivisionBayer AG Monheim Germany
| | - Mario Thevis
- Center for Preventive Doping ResearchGerman Sport University Cologne Cologne Germany
- European Monitoring Center for Emerging Doping Agents (EuMoCEDA) Cologne/Bonn Germany
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5
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Choi TL, Wong JK, Kwok WH, Curl P, Mechie S, Wan TS. Metabolic study of methylstenbolone in horses using liquid chromatography-high resolution mass spectrometry and gas chromatography-mass spectrometry. J Chromatogr A 2018; 1546:106-118. [DOI: 10.1016/j.chroma.2018.02.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/12/2018] [Accepted: 02/20/2018] [Indexed: 02/07/2023]
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New Potential Biomarker for Methasterone Misuse in Human Urine by Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry. Int J Mol Sci 2016; 17:ijms17101628. [PMID: 27669235 PMCID: PMC5085661 DOI: 10.3390/ijms17101628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/14/2016] [Accepted: 09/19/2016] [Indexed: 11/16/2022] Open
Abstract
In this study, methasterone urinary metabolic profiles were investigated by liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF-MS) in full scan and targeted MS/MS modes with accurate mass measurement. A healthy male volunteer was asked to take the drug and liquid-liquid extraction was employed to process urine samples. Chromatographic peaks for potential metabolites were hunted out with the theoretical [M - H](-) as a target ion in a full scan experiment and actual deprotonated ions were studied in targeted MS/MS experiment. Fifteen metabolites including two new sulfates (S1 and S2), three glucuronide conjugates (G2, G6 and G7), and three free metabolites (M2, M4 and M6) were detected for methasterone. Three metabolites involving G4, G5 and M5 were obtained for the first time in human urine samples. Owing to the absence of helpful fragments to elucidate the steroid ring structure of methasterone phase II metabolites, gas chromatography mass spectrometry (GC-MS) was employed to obtain structural information of the trimethylsilylated phase I metabolite released after enzymatic hydrolysis and the potential structure was inferred using a combined MS method. Metabolite detection times were also analyzed and G2 (18-nor-17β-hydroxymethyl-2α, 17α-dimethyl-androst-13-en-3α-ol-ξ-O-glucuronide) was thought to be new potential biomarker for methasterone misuse which can be detected up to 10 days.
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7
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Polet M, Van Gansbeke W, Van Eenoo P, Deventer K. Efficient approach for the detection and identification of new androgenic metabolites by applying SRM GC-CI-MS/MS: a methandienone case study. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:524-534. [PMID: 27434811 DOI: 10.1002/jms.3781] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/04/2016] [Accepted: 04/26/2016] [Indexed: 06/06/2023]
Abstract
Identification of anabolic androgenic steroids (AAS) is a vital issue in doping control and toxicology, and searching for metabolites with longer detection times remains an important task. Recently, a gas chromatography chemical ionization triple quadrupole mass spectrometry (GC-CI-MS/MS) method was introduced, and CI, in comparison with electron ionization (EI), proved to be capable of increasing the sensitivity significantly. In addition, correlations between AAS structure and fragmentation behavior could be revealed. This enables the search for previously unknown but expected metabolites by selection of their predicted transitions. The combination of both factors allows the setup of an efficient approach to search for new metabolites. The approach uses selected reaction monitoring which is inherently more sensitive than full scan or precursor ion scan. Additionally, structural information obtained from the structure specific CI fragmentation pattern facilitates metabolite identification. The procedure was demonstrated by a methandienone case study. Its metabolites have been studied extensively in the past, and this allowed an adequate evaluation of the efficiency of the approach. Thirty three metabolites were detected, including all relevant previously discovered metabolites. In our study, the previously reported long-term metabolite (18-nor-17β-hydroxymethyl,17α-methyl-androst-1,4,13-trien-3-one) could be detected up to 26 days by using GC-CI-MS/MS. The study proves the validity of the approach to search for metabolites of new synthetic AAS and new long-term metabolites of less studied AAS and illustrates the increase in sensitivity by using CI. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Michael Polet
- Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Doping Control Laboratory, Technologiepark 30 B, B-9052, Zwijnaarde, Belgium
| | - Wim Van Gansbeke
- Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Doping Control Laboratory, Technologiepark 30 B, B-9052, Zwijnaarde, Belgium
| | - Peter Van Eenoo
- Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Doping Control Laboratory, Technologiepark 30 B, B-9052, Zwijnaarde, Belgium
| | - Koen Deventer
- Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Doping Control Laboratory, Technologiepark 30 B, B-9052, Zwijnaarde, Belgium
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Cooper ER, McGrath KC, Li X, Akram O, Kasz R, Kazlauskas R, McLeod MD, Handelsman DJ, Heather AK. The use of tandem yeast and mammalian cellin vitroandrogen bioassays to detect androgens in internet-sourced sport supplements. Drug Test Anal 2016; 9:545-552. [DOI: 10.1002/dta.2000] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/20/2016] [Accepted: 04/22/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Elliot R. Cooper
- School of Life Sciences; Faculty of Science, University of Technology; Broadway NSW Australia
| | - Kristine C.Y. McGrath
- School of Life Sciences; Faculty of Science, University of Technology; Broadway NSW Australia
| | - Xiaohong Li
- School of Life Sciences; Faculty of Science, University of Technology; Broadway NSW Australia
- Department of Endocrinology; Dezhou People's Hospital; China
| | - Omar Akram
- ANZAC Research Institute; University of Sydney, Concord Hospital; NSW Australia
| | - Robert Kasz
- School of Life Sciences; Faculty of Science, University of Technology; Broadway NSW Australia
| | | | - Malcolm D. McLeod
- Research School of Chemistry; Australian National University; Canberra ACT Australia
| | - David J. Handelsman
- ANZAC Research Institute; University of Sydney, Concord Hospital; NSW Australia
| | - Alison K. Heather
- Department of Physiology; Otago School of Medical Sciences., University of Otago; Dunedin New Zealand
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Geldof L, Lootens L, Decroix L, Botrè F, Meuleman P, Leroux-Roels G, Deventer K, Van Eenoo P. Metabolic studies of prostanozol with the uPA-SCID chimeric mouse model and human liver microsomes. Steroids 2016; 107:139-48. [PMID: 26774429 DOI: 10.1016/j.steroids.2016.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/18/2015] [Accepted: 01/07/2016] [Indexed: 11/22/2022]
Abstract
Anabolic androgenic steroids are prohibited by the World Anti-Doping Agency because of their adverse health and performance enhancing effects. Effective control of their misuse by detection in urine requires knowledge about their metabolism. In case of designer steroids, ethical objections limit the use of human volunteers to perform excretion studies. Therefore the suitability of alternative models needs to be investigated. In this study pooled human liver microsomes (HLM) and an uPA(+/+)-SCID chimeric mouse model were used to examine the metabolism of the designer steroid prostanozol as a reference standard. Metabolites were detected by GC-MS (full scan) and LC-MS/MS (precursor ion scan). In total twenty-four prostanozol metabolites were detected with the in vitro and in vivo metabolism studies, which could be grouped into two broad classes, those with a 17-hydroxy- and those with a 17-keto-substituent. Major first phase metabolic sites were tentatively identified as C-3'; C-4 and C-16. Moreover, 3'- and 16β-hydroxy-17-ketoprostanozol could be unequivocally identified, since authentic reference material was available, in both models. Comparison with published data from humans showed a good correlation, except for phase II metabolism. As metabolites were in contrast to the human studies predominantly present in the free fraction. Two types of metabolites ((di)hydroxylated prostanozol metabolites) that have not been described before could be confirmed in a real positive doping control sample. Hence, the results provide further evidence for the applicability of chimeric mice and HLM to perform metabolism studies of designer steroids.
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Affiliation(s)
- Lore Geldof
- Doping Control Laboratory (DoCoLab), Technologiepark 30 B, B-9052 Zwijnaarde, Belgium.
| | - Leen Lootens
- Doping Control Laboratory (DoCoLab), Technologiepark 30 B, B-9052 Zwijnaarde, Belgium
| | - Lieselot Decroix
- Doping Control Laboratory (DoCoLab), Technologiepark 30 B, B-9052 Zwijnaarde, Belgium
| | - Francesco Botrè
- Antidoping Lab, Federazione Medico Sportiva Italiana (FMSI), Largo Giulio Onesti 1, I-00197 Rome, Italy
| | - Philip Meuleman
- Center for Vaccinology (CEVAC), Ghent University and Hospital, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Geert Leroux-Roels
- Center for Vaccinology (CEVAC), Ghent University and Hospital, De Pintelaan 185, B-9000 Ghent, Belgium
| | - Koen Deventer
- Doping Control Laboratory (DoCoLab), Technologiepark 30 B, B-9052 Zwijnaarde, Belgium
| | - Peter Van Eenoo
- Doping Control Laboratory (DoCoLab), Technologiepark 30 B, B-9052 Zwijnaarde, Belgium
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10
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Geldof L, Tudela E, Lootens L, van Lysebeth J, Meuleman P, Leroux-Roels G, van Eenoo P, Deventer K. In vitroandin vivometabolism studies of dimethazine. Biomed Chromatogr 2016; 30:1202-9. [DOI: 10.1002/bmc.3668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/20/2015] [Accepted: 12/04/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Lore Geldof
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
| | - Eva Tudela
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
| | - Leen Lootens
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
| | - Jasper van Lysebeth
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
| | - Phillip Meuleman
- Center for Vaccinology; Ghent University and Hospital; De Pintelaan 185 B-9000 Ghent Belgium
| | - Geert Leroux-Roels
- Center for Vaccinology; Ghent University and Hospital; De Pintelaan 185 B-9000 Ghent Belgium
| | - Peter van Eenoo
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
| | - Koen Deventer
- Doping Control Laboratory; Ghent University; Technologiepark 30 B B-9052 Zwijnaarde Belgium
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11
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Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol 2016; 13:89-100. [PMID: 26074745 PMCID: PMC4462045 DOI: 10.2174/1570159x13666141210224756] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/25/2014] [Accepted: 10/25/2014] [Indexed: 01/02/2023] Open
Abstract
Anabolic androgenic steroids (AAS) are some of the most common performance
enhancing drugs (PED) among society. Despite the broad spectrum of adverse effects and legal
consequences, AAS are illicitly marketed and distributed in many countries. To circumvent existing
laws, the chemical structure of AAS is modified and these designer steroids are sold as nutritional
supplements mainly over the Internet. Several side effects are linked with AAS abuse. Only little is
known about the pharmacological effects and metabolism of unapproved steroids due to the absence
of clinical studies. The large number of designer steroid findings in dietary supplements and the
detection of new compounds combined with legal loopholes for their distribution in many countries
show that stricter regulations and better information policy are needed.
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Affiliation(s)
- Jan Felix Joseph
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
| | - Maria Kristina Parr
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany
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12
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Current status and recent advantages in derivatization procedures in human doping control. Bioanalysis 2015; 7:2537-56. [DOI: 10.4155/bio.15.172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Derivatization is one of the most important steps during sample preparation in doping control analysis. Its main purpose is the enhancement of chromatographic separation and mass spectrometric detection of analytes in the full range of laboratory doping control activities. Its application is shown to broaden the detectable range of compounds, even in LC–MS analysis, where derivatization is not a prerequisite. The impact of derivatization initiates from the stage of the metabolic studies of doping agents up to the discovery of doping markers, by inclusion of the screening and confirmation procedures of prohibited substances in athlete's urine samples. Derivatization renders an unlimited number of opportunities to advanced analyte detection.
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13
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Rahnema CD, Crosnoe LE, Kim ED. Designer steroids - over-the-counter supplements and their androgenic component: review of an increasing problem. Andrology 2015; 3:150-5. [DOI: 10.1111/andr.307] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 10/19/2014] [Accepted: 10/31/2014] [Indexed: 12/26/2022]
Affiliation(s)
- C. D. Rahnema
- Division of Urology; Department of Surgery; University of Tennessee Graduate School of Medicine; Knoxville TN USA
| | - L. E. Crosnoe
- Division of Urology; Department of Surgery; University of Tennessee Graduate School of Medicine; Knoxville TN USA
| | - E. D. Kim
- Division of Urology; Department of Surgery; University of Tennessee Graduate School of Medicine; Knoxville TN USA
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Thevis M, Kuuranne T, Geyer H, Schänzer W. Annual banned-substance review: analytical approaches in human sports drug testing. Drug Test Anal 2014; 7:1-20. [DOI: 10.1002/dta.1769] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 12/01/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Mario Thevis
- Center for Preventive Doping Research - Institute of Biochemistry; German Sport University Cologne; Am Sportpark Müngersdorf 6 50933 Cologne Germany
- European Monitoring Center for Emerging Doping Agents; Cologne Germany
| | - Tiia Kuuranne
- Doping Control Laboratory; United Medix Laboratories; Höyläämötie 14 00380 Helsinki Finland
| | - Hans Geyer
- Center for Preventive Doping Research - Institute of Biochemistry; German Sport University Cologne; Am Sportpark Müngersdorf 6 50933 Cologne Germany
| | - Wilhelm Schänzer
- Center for Preventive Doping Research - Institute of Biochemistry; German Sport University Cologne; Am Sportpark Müngersdorf 6 50933 Cologne Germany
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